<p>
  <span *ngFor="let start of starts" class="glyphicon glyphicon-star"
  [class.glyphicon-star-empty]="start">
  </span>
  <span>&nbsp;{{rating | number: '1.1-1'}}&nbsp;星</span>
  <br>
  <button type="button" class="btn btn-default" (click)="buyItNow($event)">立即购买</button>
</p>
